1. Field of the Invention
The present invention relates to the field of surgery and, in particular, to an apparatus and surgical methods for repairing deformities in the proximal, middle or distal phalanx of the toe.
2. Description of the Related Art
A human forefoot consists of five metatarsals and five toes. Each toe of a foot consists of three bones, except for the big toe which consists of two. The three bones of each toe are the proximal phalanx, the middle phalanx and the distal phalanx, except the big toe which has only distal and proximal phalanxes/phalanges.
The joints of the forefoot are: (i) metatarsal phalangeal (MTP) joint; (ii) proximal interphalangeal (PIP) joint; and (iii) distal interphalangeal (DIP) joint. The MTP joint is the joint between the metatarsal and the proximal phalanx of the adjacent toe. The PIP joint is the joint between the proximal phalanx and the middle phalanx of each toe. The DIP joint is the joint between the middle phalanx and the distal phalanx of each toe.
The common deformities associated with the forefoot are hammer toes, claw toes and mallet toes. A hammertoe is a deformity of the second, third or fourth toes. In this condition, the toe is bent at the middle joint, so that it resembles a hammer. A claw toe is a toe that is contracted at the PIP and DIP joints due to tightening of ligaments and tendons causing the joints to curl downwards. Claw toes may occur in any toe, except the big toe. A mallet toe is a deformity where the most distant joint points downward; mostly common in a patient's second toe whose second toe is the longest toe. A painful callous can form at the tip of a mallet toe.
Treatment for the above deformities depends on the severity of the deformity. Conservative treatment starts with new shoes that have soft, roomy toe boxes; the treatment may involve toe exercises to stretch and strengthen the muscles. In some cases, surgery—arthroplasty, arthrodesis—may be necessary if the toe deformity causes chronic pain. Surgical treatments are aimed at loosening up the contracted toe joints to allow them to align properly or at fusing the bones to prevent a recurrence of the problem.
Arthroplasty is a surgical procedure used to treat toe deformities in which a podiatric surgeon makes an incision along the toe and trims the head of the proximal phalanx, allowing the toe to straighten. Arthrodesis is a surgical procedure used to fuse two bones together, typically the proximal and middle phalanges. A podiatric surgeon removes the cartilage from the base of the middle phalanx and fixes the bones together with a removable pin.
A commonly used device in surgical procedures is a metal K-wire, which protrudes through the tip of the toe and may be removed as an outpatient several weeks after the surgery. The disadvantages of this technique is the inconvenience, the potential infection associated with the protruding wire and late flexion deformity at the proximal interphalangeal joint as a result of delayed union at the joint.
Thus, there is a need for an apparatus and a surgical technique that is simple, flexible and is performed by a minimally invasive lateral approach, for arthroplasty and/or the fusion of the proximal, middle and distal phalanx of the toe.